If a software error corrupts a data object, or if erroneous data updates the data object, a data protection administrator may restore the data object to a previous state that does not include the corrupted or erroneous data. A backup/restore application executes a backup operation either occasionally or continuously to enable this restoration, storing a copy of each desired data object state (such as the values of data and these values' embedding in a database's data structures) within dedicated backup files. When the data protection administrator decides to return the data object to a previous state, the data protection administrator specifies the desired previous state by identifying a desired point in time when the data object was in this state, and instructs the backup/restore application to execute a restore operation to restore a copy of the corresponding backup files for that state to the data object. A backup/restore application may create a full backup file that includes all of a data object or the parts of the data object that are used. A backup/restore application may also create an incremental backup file that includes only changes made to the data object since a selected time, such as a previous backup of the data object.
A data object may be stored on a storage array, which is a disk storage system that includes multiple disk drives. Unlike a disk enclosure, a storage array has cache memory and advanced functionality, such as virtualization and Redundant Array of Independent Disks (RAID). A data protection administrator may manage a backup/restore application to create backups files of data objects and store the backup files of data objects on multiple storage arrays.
Some application servers, such as Microsoft's Exchange Server, include database availability groups, which offer a high-availability and disaster-recovery solution that provides an enterprise-level alternative to database mirroring. A database availability group maximizes the availability of a set of user databases for an enterprise, and supports a failover environment for a discrete set of user databases that fail over together from one server, or node, in a cluster to another server, or node, in the cluster. A database availability group supports a set of read-write active copies of a database and other sets of corresponding passive copies of the database.